The invention relates to a handling device for drill pipes used for deep drilling, e.g. for oil or natural gas exploration. For such a handling device, the designation “pipe handler” has established itself in the technical terminology and accordingly, the term “pipe handler” is used hereinafter as a synonym for the term “handling unit for drill pipe”. A pipe handler is part of a so-called top drive, thus the drive unit vertically movable in the mast of a drilling rig, said drive unit comprising a drive aggregate, usually a motor, which sets the drill pipe in rotational movement for the drilling process. The top drive is divided into a fixed and a rotatable part. The fixed part comprises the drive aggregate, and the power supply and the connection for receiving or transmitting electrical signals for controlling and/or monitoring the top drive is carried out via the fixed part. The pipe handler is the rotatable part and the aggregates of the pipe handler are supplied via a hydraulic rotary feedthrough between the fixed and the rotatable parts of the top drive, namely in that hydraulic actuating elements, in particular pressure cylinders, and the like are pressurized by means of a hydraulic fluid with a pressure, e.g. for moving a so-called elevator bail or for activating holding grippers provided on a so-called torque arm for drill pipes.
Specifically for the elevator bails of the pipe handler, pivotability is provided because the elevator bails (usually two) carry on their end a so-called drill pipe elevator in order to remove drill pipe elements from storage and to deliver the removed drill pipe element to the holding gripper at the end of the torque arm. A certain amount of drill pipe elements is normally provided for storage vertically adjacent to or on the mast of the drilling rig and for this purpose, a so-called finger board is provided which is located in the region of the upper end of the stored drill pipe elements. Up to now, removing drill pipe elements from their storage position, but also the other way round, namely depositing drill pipe elements into a storage position, is carried out by manual control. For this, the top drive is moved into an adequate vertical position within the mast which allows picking up or depositing drill pipe elements. As soon as the top drive has reached this position, said elevator bail or each elevator bail is pivoted and a drill pipe element is picked up or deposited with the drill pipe elevator. However, a disadvantage of these previous implementations is that it is substantially left to the attention of the operator to carry out the necessary control processes for initiating and completing such handling processes. If, e.g., after depositing a drill pipe element, the elevator bails remain pivoted, a downward movement of the top drive is normally not possible without having to fear that the ends of an elevator bail contact the finger board or other elements in or on the mast of the drilling rig. It is in particular critical if in this manner damage is caused to the mast of the drilling rig or parts thereof which, in the worst case, can result in damage to persons, e.g. in that the finger board is damaged on which normally operators walk for picking up or depositing drill pipe elements.
Accordingly, it is an object of the invention to provide a pipe handler as a handling unit for drill pipes, a top drive comprising such a pipe handler, and a method for the operation or use of these units, wherein the above-mentioned disadvantages are avoided, and in particular to provide corresponding devices and methods by means of which a position monitoring of the pipe handler or for the pipe handler and/or the top drive with pipe handler is possible.